Staff tip



G.BEWER STAFF TIP July 30, 1940.

Filed Dec. 7, 1938 a L Y R.Z MB 0 E 6 U My .w Y A Patented July 30, 1940 UNITED STATES PATENT oFFicE 1 This invention relates to devices for facilitating the penetration into the ground, by turning, and the subsequent anchorage therein, against straight or sidewise outward pull, of articles adapted to be placed into the earth or sand, such as beach umbrellas or the like.

One of, the objects of the present invention is to provide a tip-for the staff-end of an umbrella or a similar device whereby the penetration of the tip into the ground is greatly facilitated through the constructionof the tip, in that the latter is designed to penetrate into the ground with the ,least possible resistance, when the tip is turned as it is being inserted, and to provide a relatively large ground-engaging surface area, whereby the tip is securely anchored against a direct outward pull. V

Another object of my invention is to provide a staff tip for facilitating itseasy; penetration into the ground and for securelyanchoring 'it against straightputward pullfrom the ground, and wherein the tip is so constructed as to provide a relatively broad-surfaced helix, one end of which terminates in a socket for the reception and attachment of the lower end of a staff, while the other, ground engaging end, terminates in an edged or sharpened point, and wherein the diameter of the helix approximates, does not exceed, or equals the outside diameter of the socket, and wherein the construction of the tip is such as to displace, when being driven into the ground, a minimum volume of the ground matter, and to engage with its surface areas a relatively large volume of the ground matter, when the device is in its final, anchoring position.

The foregoing and still further objects of the present invention will become more fully apparent from the ensuing description and the accompanying drawing, forming a part of my disclosure, and wherein Fig. 1 is an elevation of a beach umbrella provided with my tip of the presently preferred construction.

Fig. 2 is an enlarged elevation of my tip, and

Fig. 3 is a cross sectional view taken on lines 3-3 of Fig. 2.

Referring now specifically to the figures, numeral l0 denotes the upper structure of a beach umbrella, while numeral ll designates the umbrella staff, the lower end of which is secured in socket portion [2 of tip [3. The construction of the operating part of the tip is similar to' an auger bit and consists of a thread formation of either a single or multiple helix. In the illustration I have shown a double helix, one helix being indicated at I4, the other at l5. Both of the helices commence at approximately diametrically opposite points of socket i2, and continue parallel to one another downwards and terminate in a common tip Hi, the edges I! of which 5 body portion of the tip, whereby I achieve a min- :15

imum displacement of the ground material by thetip body, while at thesame time I obtain a maximum surface contact by the tip areas with theg round. It is to be observed that the outer diameter of the helices approximate, do not ex- 20 ce'ed', or are equal to the outer diameterof socket "By employing" the aforedescribed construction of my staff tip, the resistance of the tip to its penetration into the ground is reduced to a min- 25 imum, due to the fact that the tip will only displace a relatively small portion of the ground matter; thus when the tip is inserted and turned in the proper direction, its engagement with the ground is greatly facilitated. 30 7 Due to the fact that the surfaces of the helices are relatively broad, and their cross sections are thin, and furthermore due to the fact that the central body portion of the tip is very slim, the effective anchoring area far exceeds the ground 35 displacing area of the tip. For this reason the anchoring of the tip is relatively easy, and once properly placed into the ground, the tip will be securely held therein against straight outward p 40 In the course of experimenting with my device, I have ascertained that the engagement between ground matter and my tip is soeffective that the tip, when placed into earth, such as garden soil, will resist an outward pull to such an extent as to cause the breaking up of a wide earth area surrounding the tip and taking with it a considerable volume of earth of sufiicient weight, which would assure safe anchorage of, for instance, a beach umbrella against an even stiff breeze from the sea.

In order to facilitate the attachment of a staff end to my tip I provide in socket [2 suitable means for the reception of either screws, bolts, nails, or 55 the like, indicated at [8, which are intended to fasten the staff material in place.

The slim central body portion or core, about which the two broad and thin-bodied helices l4 and I5 are constructed, is designated in an exaggerated fashion by broken lines 19, indicating a cylindrical formation. Actually that central body portion or core is merely theoretical and does not exceed in diameter the thickness of the sharp outer edges of the helices, the thickness of which edges is also greatly exaggerated in the drawing. Through this very light body structure of the core and the broadness and thinness of the helices, I provide the largest possible surface-contacting areas at the least possible body bulk, whereby I reduce to a minimum the resistance to the displacement of the ground by the body of the device, and consequently the resistance to its penetration into the ground, while at the same time I increase the effective ground-engaging power of the device to a maximum.

Attention is also directed to the relation between the pitch of the helices and their diameters. It will be observed from the drawing that the distance between two adjacent convolutions of the helices is approximately equal to or is but a trifle shorter than the diameter of the helices. This structural proportion between the pitch and the diameter provides just the correct incline of the convolutions which facilitates the ready penetration of the device into the ground, but at the same time assures dependable anchorage of the device in the ground and the greatest possible and effective resistance, for a given diameter of a helix, to the removal of the device from the ground through a straight, outward pull.

From the foregoing description it becomes clearly evident that I have developed a very effective instrumentality for its intended purpose, which may be readily attached to the end of a staff or of any other device which is adapted to be anchored in the ground, such as earth, sand, or similar ground formation. In order to insert and anchor my device it is only necessary to thrust its point against the ground and turn it until the entire helical formation reaches a complete ground engaging position, as indicated in Fig. 1. Although in this figure the staff of the umbrella is shown completely above the ground, it is quite obvious that through the thread-like construction of my tip it is readily made possible to cause the umbrella stafi to penetrate considerably further into the ground, if that should become advisable or necessary. However, for ordinary purposes it will sufiice that only the helical portion of my device engages ground matter.

In the drawing I have illustrated a tip provided with a double helix. It is quite obvious, however,

that a single helix will achieve the same or a similar result. By the same token my tip may be provided with more than two helices. Furthermore, I have shown only a specific construction and arrangement of the staff receiving socket; it is also obvious that different means may be employed for attaching my tip to a staff or the like. It is, therefore, evident that changes and improvements may be readily incorporated in my device, for which reason I reserve for myself the right to make such changes and improvements without departing from the broad scope of my invention, as defined in the annexed claim.

I claim:

In an anchoring device, a hollow socket provided with means for securing thereto a staff, a broad-surfaced, thin-bodied, continuous double helix extending from the socket, the outer edges of the double helix coinciding with a cylinder, the diameter of which does not exceed the largest diagonal passing through the socket, the distance between twoadjacent edges of the double helix approximating the diameter of the double helix, the device ending in a sharp-edged point formed by the gradually reducing edges of the double helix.

GEORGE BEITER. 

